经口咽寰枢椎侧块关节复位块状骨支撑植骨治疗颅底凹陷症并寰枢椎脱位

Treatment of basilar invagination associated with atlantoaxial dislocation through distracting and reducing the atlas-axis facet joint and implanting struct allograft bone by transoral approach

中文关键词:  颅底凹陷症  寰枢椎脱位  经口咽入路  复位  融合  内固定

英文关键词:Basilar invagination  Atlantoaxial dislocation  Transoral approach  Reduction  Fusion  Internal fixation

中文摘要:

  【摘要】 目的：探讨经口咽寰枢椎侧块关节牵开复位、三面皮质块状骨支撑植骨、内固定治疗颅底凹陷症合并寰枢椎脱位的价值。方法：2009年12月~2011年12月我院收治33例合并寰枢椎脱位的颅底凹陷症患者，均有脊髓压迫症状。术前寰齿间隙（ADI）3.8~12.1mm（7.9±3.9mm），齿状突顶部与Chamberlain线的垂直距离（DCL）3.0~15.6mm（9.3±6.2mm），寰枢椎垂直脱位指数（VAAI）0.35~0.51（0.46±0.07），颈髓延髓角（CMA）112°~145°（127°±13°），JOA评分7~10分。均采用经口咽寰枢椎侧块关节牵开复位、三面皮质块状髂骨支撑植骨、TARP内固定术治疗。记录手术时间、手术出血量等，观察并发症发生情况。术后随访8~23个月，平均11.5个月，复查影像学评价寰枢椎脱位复位和脊髓压迫改善情况，采用JOA评分改善率对脊髓功能改善情况进行评价，在CT扫描图像上观察螺钉位置及植骨融合情况。结果：手术时间110~185min（145±35min），出血量35~85ml（58±18ml）。共置入寰椎侧块螺钉66枚，枢椎逆向椎弓根螺钉41枚，枢椎椎体螺钉25枚。术后钉道扫描显示，寰椎螺钉均位于侧块内，2枚逆向枢椎椎弓根螺钉偏外进入椎动脉孔，导致椎动脉孔闭塞，小脑缺血梗死，其余枢椎螺钉均无偏差。术后发生咽后壁感染1例，将钢板取出后改行后路手术获得愈合。术后CT重建图像显示陷入枕骨大孔的齿状突获得较理想复位，脊髓受压解除，ADI 改善为0.2~4.5mm（2.3±2.1mm），VAAI 改善为0.6~0.84（0.74±0.08），CMA改善为140°~178°（157°±15°），与术前比较均有显著性差异（P<0.01）。植骨块镶嵌在寰枢侧块关节间隙，术后6~11个月均获骨性愈合。术后患者肢体麻木、肌肉无力等症状均较术前有明显改善，术后3个月复查JOA评分恢复至13~16分（15.2±0.9分），末次随访时为13~17分（15.3±0.8分），与术前比较均有显著性差异（P<0.01）。结论：经口咽寰枢椎侧块关节牵开复位三面皮质块状髂骨支撑植骨内固定术是治疗颅颈交界区病变的有效方法，但有一定风险和难度，应在严格掌握手术适应证和严格围手术期处理的条件下合理应用。

英文摘要:

  【Abstract】 Objectives: To investigate the clinical value for treatment of basilar invagination(assocaitaed with atlantoaxial dislocation) through distracting the atlas-axis facet joint and implanting struct allograft bone by transoral approach. Methods: From December 2009 to December 2011, 33 patients diagnosed with basilar invagination associated with atlantoaxial dislocation were treated by distracting the atlas-axis facet joint and implanting struct allograft bone through transoral approach. All patients had symptoms of spinal medulla compression. The atlas-dens index(ADI), distance from tip of dens to Chamberlain line(DCL), vertical atlantoaxial index(VAAI) and cervicomedullary angle(CMA) were measured on the radiography or CT image before and after operation to evaluate the reduction of atlantoaxial dislocation and the decompression of medulla. The function of spine was evaluated by the JOA score. The ADI, DCL, VAAI, CMA was 3.8-12.1mm(7.9±3.9mm), 3.0-15.6mm（9.3±6.2mm）, 0.35-0.51(0.46±0.07) and 112°-145°(127°±13°) respectively before operation, and the spine function ranged from 7 to 10 before surgery. All cases received operations through distracting the atlas-axis facet joint and implanting struct allograft bone and TARP plate by transoral approach. Operation time and blood loss were recorded, and complications were observed after operation. All patients were followed up for 8-23 months(mean 11.5 months), the reduction of atlas-axis facet joint dislocation and improvement of spinal cord compression were evaluated by images, the bone fusion and screw placement route were evaluated with CT reconstruction image. Results: The mean operation time was 110-185min(145±35min), and the average blood loose was 35-85ml(58±18ml). There were total 66 atlas lateral mass screws, 41 reverse axis pedicle screws and 25 axis vertebrae body screws. Among them, there were 2 reverse axis pedicle screws violated into the vertebral artery foramen, leading to cerebellum thrombosis, and the other screws were all in right place. 1 patient showed soft tissue infection after operation and then the TARP plate was taken off and changed into posterior instructation. Postoperative CT image showed the dens of axis could be pulled down form the magnum foramen to gain reduction ideally, the compressions were resolved effectively. The ADI changed to 0.2-4.5mm(2.3±2.1mm), the VAAI changed to 0.60-0.84(0.74±0.08), the CMA changed to 140°-178°(157°±15°). There were statistical differences between post and pre- operation(P<0.01), and the sypmptoms of limbs numbness and weakness improved more greatly than preoperation. The JOA scores changed to 13-16(15.2±0.9) in the third month after operation, and reached to 13-17（15.3±0.8） at the final follow-up, which all showed statistical differences compared with the preopeation(P<0.01). Conclusions: It is an effecitve operation for treatment of basilar invagination associated with atlantoaxial through distracting and reducing the atlas-axis facet joint and implanting struct allograft bone by transoral approach, however with some risk and difficulty of surgery, which should only be carried out under stricted indications and with perioperative cares. 【Key words】 Basilar invagination; Atlantoaxial dislocation; Transoral approach; Reduction; Fusion; Internal fixation